JP2002130552A - Oil well pipe screw joint with excellency in environmental conservation - Google Patents

Oil well pipe screw joint with excellency in environmental conservation

Info

Publication number
JP2002130552A
JP2002130552A JP2000323913A JP2000323913A JP2002130552A JP 2002130552 A JP2002130552 A JP 2002130552A JP 2000323913 A JP2000323913 A JP 2000323913A JP 2000323913 A JP2000323913 A JP 2000323913A JP 2002130552 A JP2002130552 A JP 2002130552A
Authority
JP
Japan
Prior art keywords
threaded joint
metal sealing
pin
country tubular
joint
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2000323913A
Other languages
Japanese (ja)
Inventor
Takuya Tsujimura
琢也 辻村
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nippon Steel Corp
Original Assignee
Sumitomo Metal Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sumitomo Metal Industries Ltd filed Critical Sumitomo Metal Industries Ltd
Priority to JP2000323913A priority Critical patent/JP2002130552A/en
Publication of JP2002130552A publication Critical patent/JP2002130552A/en
Pending legal-status Critical Current

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16LPIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
    • F16L15/00Screw-threaded joints; Forms of screw-threads for such joints
    • F16L15/001Screw-threaded joints; Forms of screw-threads for such joints with conical threads
    • F16L15/004Screw-threaded joints; Forms of screw-threads for such joints with conical threads with axial sealings having at least one plastically deformable sealing surface

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Non-Disconnectible Joints And Screw-Threaded Joints (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide an oil well pipe screw joint capable of securing hermeticity resistance and/or seizing resistance and excellent in environmental conservation. SOLUTION: The oil well pipe screw joint forming a metallic sealing part by contacting with each other for a pin part and a box part satisfies the following conditions (1) to (3): (1) An internal pressure in the metallic sealing part Pi (MPa) and a contact face pressure under load condition σr (MPa) satisfy: σr>=Pi; (2) A film thickness of the metallic sealing part applied on either the pin part or box part is 7 to 50 μ and the Vicker's hardness is not greater than 300; (3) The condition of (1) and the metallic processing condition of (2) are combined.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】本発明は、環境保全性に優れ
た油井管用ネジ継手に関し、さらに詳しくは、内部流体
に対する耐気密性に優れ、炭酸ガス(CO2)や硫化水素
(H2S)等の有毒ガスを環境中に漏らすことなく、ま
たは/および締結の際に無潤滑で、若しくは環境汚染の
恐れがない、重金属を含まないスレッドコンパウンドの
使用が可能となり、環境保全を考慮した油井管用ネジ縦
手に関するものである。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a threaded joint for oil country tubular goods having excellent environmental preservation properties, and more particularly, it has excellent airtightness against an internal fluid, carbon dioxide gas (CO 2 ) and hydrogen sulfide (H 2 S). Thread compounds that do not leak heavy toxic gases into the environment and / or that are lubricated at the time of fastening or that do not pose a risk of environmental pollution can be used without using heavy metals. It is related to the screw vertical.

【0002】[0002]

【従来の技術】最近の油井や天然ガス井(以下、単に
「油井」という)は、その深さが数千メートルにも及ぶ
ようになるとともに、その使用環境は年々厳しくなって
いる。このような油井に埋設されて使用される管材、す
なわち油井管は、ネジ継手によって相互に螺合・締結さ
れているため、締結に用いられるネジ継手は、強大な軸
力に耐え、しかも高い気密性を有するものであることが
要求される。
2. Description of the Related Art Recent oil wells and natural gas wells (hereinafter, simply referred to as "oil wells") have reached a depth of several thousand meters, and their use environment is becoming severer year by year. Since the pipe material buried and used in such an oil well, that is, the oil well pipe, is screwed and fastened to each other by a screw joint, the screw joint used for fastening withstands a strong axial force and has high airtightness. It is required to have the property.

【0003】上記の要求に応え得るネジ継手には、種々
多様なものがあり、例えば、図1および図2に示すよう
なネジ継手が従来から知られている。
[0003] There are various types of threaded joints that can meet the above demands. For example, threaded joints as shown in Figs. 1 and 2 have been known.

【0004】図1は、従来のバットレスタイプのネジ継
手を示す模式的一部破断縦断面図である。図1に示すネ
ジ継手は、API(米国石油学会)規格のSTD5Bに
規定された台形ネジを有するバットレスタイプであり、
鋼管10の管端にテーパ雄ネジ12を有するピン部11と、カ
ップリング20の両管端内周部に設けられたテーパ雌ネジ
22を有するボックス部21とからなっている。
FIG. 1 is a schematic partially broken longitudinal sectional view showing a conventional buttress type threaded joint. The threaded joint shown in FIG. 1 is a buttress type having a trapezoidal thread specified in STD5B of API (American Petroleum Institute) standard,
A pin portion 11 having a tapered male screw 12 at the pipe end of a steel pipe 10, and a tapered female screw provided at an inner peripheral portion of both pipe ends of the coupling 20.
And a box section 21 having a box 22.

【0005】図2は、従来のトルクショルダー形成用ネ
ジ無し肩部を有するネジ継手の要部を示す模式的縦断図
である。図2に示すネジ継手は「特殊継手」と呼ばれ、
ピン部11の先端部にトルクショルダー用のネジ無し肩部
13を形成する一方、ボックス部21の内側底部に前記のネ
ジ無し肩部13が当接する受け部23が形成されている。こ
のように、ネジ無し肩部13と受け面23とを当接させるこ
とによって、過剰な締め付けを抑制するとともに、相互
に接触して金属対金属のシールによる金属密封部14を形
成させて、継手の気密性を高めるようにしたものであ
る。
FIG. 2 is a schematic longitudinal sectional view showing a main part of a conventional threaded joint having a threadless shoulder for forming a torque shoulder. The threaded joint shown in Fig. 2 is called "special joint"
Screwless shoulder for torque shoulder at the tip of pin 11
On the other hand, a receiving portion 23 is formed on the inner bottom portion of the box portion 21 so that the screwless shoulder portion 13 abuts. As described above, the screwless shoulder portion 13 and the receiving surface 23 are brought into contact with each other to suppress excessive tightening and to form a metal-to-metal seal portion 14 by contact with each other to form a joint. The airtightness is improved.

【0006】従来のネジ継手では、金属密封部の設計に
関する明確な規定はないことから、充分な耐気密性が確
保できず、有毒な内部流体を漏洩するという事態の発生
もある。通常、ネジ継手の設計において、締結にともな
う焼き付きを防止するにはピン部の肉厚を薄くするのが
望ましいが、ピン部の薄肉化は耐気密性の低下要因とな
る。これに対し、ピン部の肉厚を厚くすると耐気密性は
改善されるが、耐焼き付き性が低下することになる。
[0006] In the conventional threaded joint, there is no clear regulation on the design of the metal sealing portion, so that sufficient airtightness cannot be ensured, and a situation may occur in which a toxic internal fluid leaks. Usually, in the design of a threaded joint, it is desirable to reduce the thickness of the pin portion in order to prevent seizure due to fastening, but the thinning of the pin portion causes a reduction in airtightness. On the other hand, when the thickness of the pin portion is increased, the airtightness is improved, but the seizure resistance is reduced.

【0007】ネジ継手の耐焼き付き性に関し、一旦、締
結されて油井に埋設、降下された油井管であっても、引
き上げて締結を解き、再度、締結使用することもあり、
締め戻しおよび締め付けの際に、焼き付きが発生しない
ことが要求される。
[0007] Regarding the seizure resistance of a threaded joint, even an oil well pipe that has been fastened once, buried in an oil well, and lowered, may be pulled up, loosened, and used again.
It is required that seizure does not occur during retightening and tightening.

【0008】従来には、ネジ継手の耐焼き付き性を確保
するため、潤滑剤として使用されるコンパウンドグリス
に、潤滑性能に優れる重金属を含んだものを使用してい
た。しかし、重金属を含むグリスでは耐焼き付き性が改
善されるものの、重金属による環境汚染の問題があるこ
とから、これらの使用を回避することが求められるよう
になる。したがって、ネジ継手の開発に当たり、重金属
を含まない潤滑剤を使用した場合であっても、優れた耐
焼き付き性を発揮することができるネジ継手の要請が高
まっている。
Conventionally, in order to ensure seizure resistance of a threaded joint, compound grease used as a lubricant contains a heavy metal having excellent lubrication performance. However, although grease containing heavy metals has improved seizure resistance, there is a problem of environmental pollution due to heavy metals, so that it is required to avoid using them. Therefore, in the development of a threaded joint, there is an increasing demand for a threaded joint capable of exhibiting excellent seizure resistance even when a lubricant containing no heavy metal is used.

【0009】一方、継手の表面処理としては、リン酸亜
鉛(Zn)やリン酸マンガン(Mn)等の化成皮膜処理が一
般的に使用されている。しかし、前述のように、油井環
境が厳しくなり、炭酸ガス(CO2)や硫化水素(H2S)
を含む油井が増加するにともなって、耐食性を確保する
ため、クロム(Cr)を9%以上含有する高クロムステン
レス鋼からなる油井管が採用されるようになっている。
ところが、高クロムステンレス鋼からなる油井管では、
上記の化成処理を施しても、管表面での化学反応が制限
され、被膜形成が充分に行われない。このため、これら
化成処理に代わって、ネジ継手の表面処理として、Cuメ
ッキ、ZnメッキおよびNi−Znメッキ等が実施されるよう
になっている。
On the other hand, as a surface treatment of the joint, a chemical conversion treatment such as zinc phosphate (Zn) or manganese phosphate (Mn) is generally used. However, as mentioned above, the environment of oil wells has become severe, and carbon dioxide (CO 2 ) and hydrogen sulfide (H 2 S)
As the number of oil wells containing chromium increases, oil well pipes made of high chromium stainless steel containing 9% or more of chromium (Cr) have been adopted in order to secure corrosion resistance.
However, in oil country tubular goods made of high chromium stainless steel,
Even when the above chemical conversion treatment is performed, the chemical reaction on the tube surface is limited, and the film cannot be sufficiently formed. Therefore, instead of these chemical conversion treatments, Cu plating, Zn plating, Ni-Zn plating, and the like are being performed as surface treatments of threaded joints.

【0010】したがって、過酷な油井環境に使用される
ネジ継手であっても、環境保全性を具備したネジ継手の
開発要請のもとで、望ましくは潤滑剤を使用せず、少な
くとも潤滑剤としてのコンパウンドグリスの種類に関わ
らず、優れた耐焼き付き性を発揮することができる表面
処理に関する提案が多くなされている。
Therefore, even with a threaded joint used in a severe oil well environment, a lubricant is desirably not used, and at least as a lubricant, in accordance with a request for the development of a threaded joint having environmental protection. Regardless of the type of compound grease, there have been many proposals regarding surface treatment that can exhibit excellent seizure resistance.

【0011】例えば、特開昭58−17285号公報では、Cr
が10%以上の高クロム含有鋼の継手の金属密封部(メタ
ル−メタルシール部)に、ビッカース硬度で300以下、
融点が400℃以上である金属および合金メッキを施す表
面処理法が提案されている。提案の表面処理は、具体的
には銅や亜鉛等のメッキ処理であるから、金属密封部の
耐焼き付き性を著しく向上させることが可能である。
For example, in Japanese Patent Application Laid-Open No. 58-17285, Cr
Has a Vickers hardness of 300 or less in the metal seal part (metal-metal seal part) of a high chromium content steel joint with 10% or more.
Surface treatment methods for plating metals and alloys having a melting point of 400 ° C. or higher have been proposed. Since the proposed surface treatment is specifically a plating treatment of copper, zinc, or the like, the seizure resistance of the metal sealing portion can be significantly improved.

【0012】ところが、環境汚染を回避するために、重
金属を含まないコンパウンドグリスの使用が検討されて
いない。また、メッキ処理におけるメッキ膜厚に関する
配慮がないため、膜厚のバラツキによるピン部とボック
ス部との干渉量が変動する。干渉量が過大になった場合
には、異常な面圧上昇が発生し、締め付けトルクの上昇
や焼き付きが発生する可能性もある。
However, use of compound grease containing no heavy metal has not been studied in order to avoid environmental pollution. In addition, since there is no consideration regarding the plating film thickness in the plating process, the interference amount between the pin portion and the box portion varies due to the variation in the film thickness. If the amount of interference is excessive, an abnormal increase in surface pressure may occur, which may cause an increase in tightening torque and / or burn-in.

【0013】また、特開平8−233164号公報、特開平9
−72467号公報では、継手のピン部とボックス部の接触
表面に5〜40μmの凹凸を設けるか、若しくは化成皮膜
層を設けて、二硫化モリブデン粉末を樹脂に分散混合し
た樹脂皮膜層をこれらの上に形成することによって、無
潤滑下の条件であっても耐焼き付き性に優れた表面処理
法が提案されている。しかしながら、上記の二硫化モリ
ブデン粉末に含まれる硫黄は油井管用の鋼材を腐食させ
る、硫化水素腐食の問題が明らかになっている。このた
め、二硫化モリブデンの使用が必須である表面処理法
は、そのまま炭素鋼、ステンレス鋼製のネジ継手に適用
することが困難である。
Further, Japanese Patent Application Laid-Open Nos. Hei 8-233164 and Hei 9
In JP-A-72467, a resin coating layer obtained by dispersing and mixing molybdenum disulfide powder in a resin is provided with unevenness of 5 to 40 μm or a conversion coating layer provided on the contact surface between the pin portion and the box portion of the joint. A surface treatment method having excellent seizure resistance even under non-lubricated conditions has been proposed. However, the problem of hydrogen sulfide corrosion, in which sulfur contained in the above molybdenum disulfide powder corrodes steel for oil country tubular goods, has been clarified. For this reason, it is difficult to apply the surface treatment method in which the use of molybdenum disulfide is essential to a threaded joint made of carbon steel or stainless steel as it is.

【0014】さらに、特開昭61−136087号公報でも、金
属密封部の少なくとも一方の表面荒さを管理し、所定粒
径以下の二硫化モリブデン粉末を樹脂に混合した被膜を
施した油井管用継手が提案されているが、粉末中の硫黄
が継手を腐食させることから、上記と同様に、その適用
が制限されている。
Furthermore, Japanese Patent Application Laid-Open No. 61-136087 also discloses an oil country tubular good joint in which at least one surface roughness of a metal sealing portion is controlled and a coating obtained by mixing molybdenum disulfide powder having a predetermined particle size or less with a resin is applied. Although proposed, its application is limited, as above, because sulfur in the powder corrodes the joints.

【0015】[0015]

【発明が解決しようとする課題】前述の通り、油井の高
深度化と同時に、環境の過酷化が進展する中で、油井管
用ネジ継手として要求される、耐気密性または/および
耐焼き付き性を確保して、有毒ガスを環境に漏洩せず、
または環境汚染を発生することもなく、環境保全性に優
れるネジ継手が要求されている。
As described above, as the depth of an oil well increases and the environment becomes more severe, the airtightness and / or seizure resistance required for a threaded joint for an oil well pipe have been improved. To ensure that no toxic gases leak to the environment,
Alternatively, a threaded joint that does not cause environmental pollution and has excellent environmental preservation is demanded.

【0016】このため、コンパウンドグリスに含有され
る重金属による環境汚染を回避するために、ネジ継手を
潤滑剤を使用しない条件や、重金属を含まないスレッド
コンパウンドを用いて締結することが試みられ、各種の
ネジ継手、表面処理、さらに潤滑剤の組み合わせで検討
された。しかし、いずれも十分な耐焼き付き性能が得ら
れず、逆に耐焼き付き性を重視し過ぎたため、例えば、
金属密封部の干渉量が不適切となり、内部流体を漏洩さ
せてしまう事態も発生した。
For this reason, in order to avoid environmental pollution due to heavy metals contained in the compound grease, it has been attempted to fasten the threaded joint under conditions that do not use a lubricant or with a thread compound that does not contain heavy metals. Threaded joints, surface treatments, and combinations of lubricants were studied. However, in all cases, sufficient seizure resistance was not obtained, and conversely, too much seizure resistance was emphasized.
In some cases, the interference amount of the metal sealing portion becomes inappropriate and the internal fluid leaks.

【0017】さらに、油井用ネジ継手の表面処理とし
て、二硫化モリブデンを含有する樹脂皮膜が開発され、
実用化が試みられたが、前述の硫化水素腐食の問題か
ら、油井管用ネジ継手としては適用できないという問題
がある。
Further, as a surface treatment of a threaded joint for oil wells, a resin film containing molybdenum disulfide has been developed,
Attempts have been made to put it into practical use, but there is a problem that it cannot be applied as a threaded joint for oil country tubular goods due to the aforementioned problem of hydrogen sulfide corrosion.

【0018】本発明は、従来の油井用ネジ継手が有する
問題点に鑑みてなされたものであり、金属密封部での接
触面圧を負荷内圧との関係で管理することによって、耐
気密性を向上させることができ、CO2やH2S等の有毒ガ
スを環境中に漏らすことなく、または/および、表面処
理としてピン部またはボックス部のいずれか一方に所定
のメッキ処理を施すことによって、耐焼き付き性が確保
でき、潤滑剤を使用しない場合でも、若しくは環境汚染
の恐れがない潤滑剤を使用する場合でも、焼き付きを発
生することなく締め付け、締め戻しが可能となり、環境
保全性に優れた油井管用ネジ継手を提供することを目的
としている。
The present invention has been made in view of the problems of the conventional oil well threaded joints, and has improved airtightness by managing the contact surface pressure at the metal sealing portion in relation to the load internal pressure. Without causing toxic gases such as CO 2 and H 2 S to leak into the environment, and / or by subjecting either the pin portion or the box portion to a predetermined plating process as a surface treatment, Seizure resistance can be ensured, and even when no lubricant is used or when a lubricant that does not cause environmental pollution is used, tightening and retightening can be performed without seizure, resulting in excellent environmental conservation. It is intended to provide a threaded joint for oil country tubular goods.

【0019】[0019]

【課題を解決するための手段】本発明は、下記(1)〜(3)
の油井用ネジ継手を要旨としている。 (1) 先端にネジ無し肩部が形成されたテーパ雄ネジを管
端外周面に有するピン部と、前記のネジ無し肩部が当接
する受け部が形成されたテーパ雌ネジを内周面に有する
ボックス部とが相互に接触して金属密封部を形成する油
井管用ネジ継手であって、前記金属密封部における内圧
負荷状態での接触面圧σr(MPa)が下記(a)〜(c)式を満た
すことを特徴とする環境保全性に優れた油井管用ネジ継
手である。
The present invention provides the following (1) to (3)
The gist is a threaded joint for oil wells. (1) On the inner peripheral surface, a pin portion having a tapered male screw with a threadless shoulder formed at the tip on the outer peripheral surface of the tube end, and a tapered female screw having a receiving portion with which the screwless shoulder abuts are formed. A threaded joint for an oil country tubular good in which a box portion having a metal contact portion is formed in contact with each other, wherein a contact surface pressure σr (MPa) in an internal pressure load state in the metal seal portion has the following (a) to (c). This is a threaded joint for oil country tubular goods excellent in environmental conservation characterized by satisfying the formula.

【0020】[0020]

【数2】 ただし、Pi:内圧 (MPa) Pm:締め付け状態での金属密封部の接触面圧(MPa) δ :干渉量(mm) E :縦弾性係数 R1:ピン部の内半径(mm) R2:金属密封部の外半径(mm) R3:ボックス部の外半径(mm) (2) 先端にネジ無し肩部が形成されたテーパ雄ネジを管
端外周面に有するピン部と、前記のネジ無し肩部が当接
する受け部が形成されたテーパ雌ネジを内周面に有する
ボックス部とが相互に接触して金属密封部を形成する油
井管用ネジ継手であって、前記ピン部またはボックス部
のいずれか一方の金属密封部に施されたメッキ処理の膜
厚を7〜50μとし、ビッカース硬度で300以下とするこ
とを特徴とする環境保全性に優れた油井管用ネジ継手で
ある。 (3) 上記(1)の(a)〜(c)式を満たす条件と、上記(2)のメ
ッキ処理条件とを組み合わせた油井用ネジ継手である。
これにより、耐気密性と耐焼き付き性とを兼備し、さら
に環境保全性を向上させることができるので、望まし
い。ただし、金属密封部の外半径R2(mm)は、メッキ
処理前の外半径R2'(mm)、膜厚Wt(μ)とした場合
に、R2=R2'+0.001Wtの関係を満足する。
(Equation 2) However, Pi: internal pressure (MPa) Pm: contact surface pressure of metal sealing part in tightened state (MPa) δ: interference amount (mm) E: longitudinal elastic modulus R1: inner radius of pin part (mm) R2: metal sealing R3: Outer radius of the box part (mm) (2) Pin part having a tapered male screw with a screwless shoulder at the tip on the outer peripheral surface of the pipe end, and the screwless shoulder part A threaded joint for an oil country tubular good in which a box portion having a tapered female screw having an inner peripheral surface formed with a receiving portion with which an abutment comes into contact with each other to form a metal-sealed portion, wherein the pin portion or the box portion This is a threaded joint for oil country tubular goods excellent in environmental preservation, characterized in that the thickness of the plating treatment applied to one of the metal sealing portions is 7 to 50 μm and the Vickers hardness is 300 or less. (3) An oil well threaded joint combining the conditions satisfying the expressions (a) to (c) of the above (1) and the plating treatment conditions of the above (2).
This is desirable because it has both airtightness resistance and seizure resistance and can further improve environmental conservation. However, the outer radius R2 (mm) of the metal sealing portion satisfies the relationship of R2 = R2 '+ 0.001 Wt when the outer radius R2' (mm) and the film thickness Wt (μ) before plating.

【0021】[0021]

【発明の実施の形態】本発明の油井管用ネジ継手は、金
属密封部における耐気密性を確保し、内部流体の漏洩を
防ぐことによって、環境保全を可能にし、または/およ
び、金属密封部に潤滑性に優れた表面処理を施すことに
よって、潤滑剤を使用しない場合であっても、また環境
汚染の要因となる重金属を含まないスレッドコンパウン
ドを使用する場合であっても、繰り返しの締め付け、締
め戻しに際し、優れた耐焼き付き性を発揮して環境保全
を可能にすることを特徴している。
BEST MODE FOR CARRYING OUT THE INVENTION The threaded joint for oil country tubular goods according to the present invention ensures environmental protection by ensuring airtightness in a metal sealing portion and preventing leakage of an internal fluid, and / or providing a metal sealing portion. By applying a surface treatment with excellent lubrication properties, even if no lubricant is used, or even if a thread compound that does not contain heavy metals that cause environmental pollution is used, repeated tightening and tightening can be performed. When returning, it is characterized by exhibiting excellent seizure resistance and enabling environmental conservation.

【0022】以下、本発明の油井管用ネジ継手の特徴
を、耐気密性の確保と、耐焼き付き性の確保とに区分し
て説明する。 1.耐気密性の確保について 通常、油井管用ネジ継手の締結は、有効径が同一である
ピン部とボックス部とからなる継手が基準位置で螺合お
よび接触してのち、さらに所定の締め付けが行われる。
このときの継手半径方向の締め付け代(mm)が干渉量と
して管理される。そして、発明者らの検討によれば、ネ
ジ継手の金属密封部における耐気密性は、金属密封部に
発生する干渉量(mm)の影響を受けることが明らかにな
る。
Hereinafter, the features of the threaded joint for oil country tubular goods according to the present invention will be described by dividing them into securing airtightness and securing seizure resistance. 1. About securing of airtightness Normally, the screw joint for oil country tubular goods is screwed and contacted at the reference position at the reference position after the joint consisting of the pin portion and the box portion having the same effective diameter, and then further predetermined tightening is performed. .
The tightening allowance (mm) in the joint radial direction at this time is managed as the interference amount. According to the study by the inventors, it becomes clear that the airtightness of the metal joint of the threaded joint is affected by the amount of interference (mm) generated in the metal joint.

【0023】図3は、本発明のトルクショルダー形成用
ネジ無し肩部を有するネジ継手の要部を示す模式的縦断
図である。以下に、図3に基づいて、本発明の油井管用
ネジ継手の耐気密性について詳細に説明する。なお、以
下の説明は、両端に2つのボックス部を設けたカップリ
ングを用いた場合に基づいているが、鋼管の1端にピン
部を、他端にボックス部を設けて管同士を接続する、い
わゆるインテグラル方式の場合であってもよい。さら
に、ボックス部またはピン部がアプセット加工された管
端部に形成される場合であってもよい。
FIG. 3 is a schematic longitudinal sectional view showing a main part of a threaded joint having a threadless shoulder for forming a torque shoulder according to the present invention. Hereinafter, the airtightness of the threaded joint for oil country tubular goods of the present invention will be described in detail with reference to FIG. The following description is based on the case where a coupling having two box portions provided at both ends is used. However, a pin portion is provided at one end of the steel pipe, and a box portion is provided at the other end to connect the pipes. In other words, a so-called integral system may be used. Furthermore, the case where a box part or a pin part is formed in the upset processed pipe end part may be sufficient.

【0024】図3に示すように、本発明の油井管用ネジ
継手は、前記の図2に示したのと同様に、一方の鋼管10
の管端部の先端外周面に形成されたテーパ雄ネジ12を有
するピン部11と、カップリング20の管端内周面に形成さ
れたテーパ雌ネジ22を有するボックス部21とからなって
いる。また、ピン部11の先端には、トルクショルダー用
のネジ無し肩部13が形成されており、またボックス部21
の内側底部には、前記のネジ無し肩部13が当接する受け
部23がそれぞれ形成され、相互に接触して金属密封部14
を形成するようになっている。このときのピン部11、ボ
ックス部21および金属密封部14の主要寸法を、ピン部の
内半径R1、金属密封部の外半径R2、およびボックス部
の外半径R3で示している。
As shown in FIG. 3, the threaded joint for oil country tubular goods according to the present invention is similar to that shown in FIG.
It comprises a pin portion 11 having a tapered male screw 12 formed on the outer peripheral surface of the distal end of the tube end, and a box portion 21 having a tapered female screw 22 formed on the inner peripheral surface of the tube end of the coupling 20. . Further, a screwless shoulder 13 for a torque shoulder is formed at the tip of the pin portion 11, and a box portion 21 is formed.
At the bottom of the inside, receiving portions 23 with which the screwless shoulder portions 13 abut are formed, and contact each other to form a metal sealing portion 14.
Is formed. The main dimensions of the pin portion 11, the box portion 21 and the metal sealing portion 14 at this time are indicated by the inner radius R1 of the pin portion, the outer radius R2 of the metal sealing portion, and the outer radius R3 of the box portion.

【0025】上記のように構成されたネジ継手を締め付
けて、金属密封部14に干渉量δ(mm)を発生させた状態
では、焼ばめによる接触応力で結合される円筒同士の組
み合わせとみなすことができ、金属密封部14における平
均面圧Pmは、下記(c)式によって算出することができ
る。
When the screw joint having the above-described structure is tightened to generate an interference amount δ (mm) in the metal sealing portion 14, it is regarded as a combination of cylinders connected by a contact stress by shrink fitting. The average surface pressure Pm in the metal sealing portion 14 can be calculated by the following equation (c).

【0026】[0026]

【数3】 ここで、油井管用のネジ継手では、通常、ピン部11が形
成される鋼管10とボックス部21が形成されるカップリン
グ20の材質は同一である。これは、ピン部11とボックス
部21の材質が異なることによる、電位差腐食等のトラブ
ルを回避するためである。したがって、上記の(c)式中
で縦弾性係数Eはピン部11およびボックス部21は同一と
して扱っている。
(Equation 3) Here, in the threaded joint for oil country tubular goods, the material of the steel pipe 10 in which the pin portion 11 is formed and the material of the coupling 20 in which the box portion 21 is formed are usually the same. This is to avoid troubles such as potential difference corrosion due to different materials of the pin portion 11 and the box portion 21. Accordingly, in the above equation (c), the pin portion 11 and the box portion 21 treat the longitudinal elastic modulus E as the same.

【0027】次に、ネジ継手が内圧負荷のみ状態での影
響を確認するには、干渉量δ=0の状態で組み合わせ
後、内側円筒に相当するピン部11に内圧Piが負荷され
た場合を想定する必要がある。このとき、金属密封部で
は内圧Piによって、下記(b’)式で求められる応力σp
が発生する。
Next, in order to confirm the effect when the screw joint is in the state of only the internal pressure load, a case where the internal pressure Pi is applied to the pin portion 11 corresponding to the inner cylinder after the combination with the interference amount δ = 0 is considered. It is necessary to assume. At this time, the stress σp obtained by the following equation (b ′) is applied to the metal sealed portion by the internal pressure Pi.
Occurs.

【0028】[0028]

【数4】 油井での実作業と合致させるように、継手を締め付け状
態(干渉量δ発生)にしたのち、ピン部11に内圧Piを
負荷した状態を想定すると、金属密封部14における平均
面圧σrは、σr=Pm+σpで表すことができ、下記(b)
式として整理できる。
(Equation 4) Assuming that the joint is tightened (interference amount δ is generated) and the internal pressure Pi is applied to the pin portion 11 so as to match the actual operation in the oil well, the average surface pressure σr in the metal sealing portion 14 is σr = Pm + σp, which can be expressed by the following (b)
Can be organized as an expression.

【0029】[0029]

【数5】 内部流体の漏洩を防止して継手の気密性を確保するに
は、金属密封部における平均面圧σrと内圧Piとは、下
記(a)式の関係を保持する必要がある。 σr ≧ Pi ・・・ (a) 上記(a)式の条件を満たすネジ継手であれば、油井用と
して要求される耐気密性が確保でき、内部流体がCO2
2S等の有毒ガス、またはこれらを含有する液体であ
っても、環境中に漏らすことがなく、優れた環境保全性
を発揮することができる。
(Equation 5) In order to prevent the leakage of the internal fluid and secure the airtightness of the joint, the average surface pressure σr and the internal pressure Pi in the metal sealing portion need to maintain the relationship of the following equation (a). σr ≧ Pi (a) If the threaded joint satisfies the condition of the above equation (a), the airtightness required for oil wells can be secured, and the internal fluid is a toxic gas such as CO 2 or H 2 S. Or even a liquid containing them can exhibit excellent environmental preservation without leaking into the environment.

【0030】上述の(a)〜(c)式から明らかなように、干
渉量δが過小であると、耐気密性が確保できず、内部流
体が漏洩する恐れがある。一方、干渉量δが過大になる
と、締め付けトルクが著しく増大することになるので、
焼き付き発生の恐れがある。したがって、ネジ継手の仕
様設計に当たっては、適切な干渉量δを金属密封部で確
保できるようにする必要がある。 2.耐焼き付き性の確保について ネジ継手のピン部11またはボックス部21のいずれか一方
の金属密封部14にCuメッキやZnメッキ等の表面処理を施
すことが有効である。表面処理をいずれか一方に施すこ
ととしているのは、メッキ膜厚の管理を容易にするため
である。
As is apparent from the above equations (a) to (c), when the interference amount δ is too small, the airtightness cannot be secured, and the internal fluid may leak. On the other hand, if the interference amount δ is excessive, the tightening torque will increase significantly,
There is a risk of burn-in. Therefore, in designing the specifications of the threaded joint, it is necessary to ensure that an appropriate amount of interference δ can be ensured by the metal sealing portion. 2. Ensuring Seizure Resistance It is effective to apply a surface treatment such as Cu plating or Zn plating to one of the metal sealing portion 14 of the pin portion 11 and the box portion 21 of the threaded joint. The reason why the surface treatment is performed on either one is to facilitate the control of the plating film thickness.

【0031】メッキ膜厚Wtを7〜50μで管理する必要が
ある。膜厚Wtが7μ以下では、継手のピン部11またはボ
ックス部21の加工面の表面粗さ以下となり、締め付け時
に焼き付きが発生する恐れがある。一方、膜厚Wtが過大
に増加すると、メッキ膜の密着性に問題が発生すること
から、50μ以下に規定した。
It is necessary to control the plating film thickness Wt at 7 to 50 μm. When the film thickness Wt is 7 μm or less, the surface roughness of the processed surface of the pin portion 11 or the box portion 21 of the joint is not more than the surface roughness, and there is a possibility that seizure may occur during tightening. On the other hand, when the film thickness Wt is excessively increased, a problem occurs in the adhesion of the plating film.

【0032】さらに、メッキ膜厚Wtが増大すると、ネジ
全体の干渉量が増加し、過大な締め付けトルクが発生す
ることになる。したがって、このような観点からも、メ
ッキ膜厚を管理して、適正な干渉量δが確保できるよう
する必要がある。したがって、前記(b)式に示す金属密
封部の外半径R2(mm)は、メッキ処理前の外半径R2'
(mm)とした場合に、R2=R2'+0.001Wtの関係を管理
する。
Further, when the plating film thickness Wt increases, the interference amount of the whole screw increases, and an excessive tightening torque is generated. Therefore, from such a viewpoint, it is necessary to control the plating film thickness so as to ensure an appropriate interference amount δ. Therefore, the outer radius R2 (mm) of the metal sealing portion shown in the above equation (b) is equal to the outer radius R2 'before plating.
(Mm), the relationship of R2 = R2 '+ 0.001 Wt is managed.

【0033】本発明のメッキ処理では、ビッカース硬度
(Hv)で300以下とする必要がある。Hv300以下と硬度
が低ければ、継手の締め付け時にメッキ膜が潤滑効果を
発揮して、焼き付きの発生を有効に防止するからであ
る。
In the plating treatment of the present invention, the Vickers hardness (Hv) needs to be 300 or less. If the hardness is as low as Hv300 or less, the plating film exerts a lubricating effect when the joint is tightened, thereby effectively preventing the occurrence of seizure.

【0034】本発明のネジ継手では、上記のメッキ処理
を施すことによって、無潤滑、すなわち、何らのグリス
を用いない場合であっても、または、潤滑剤として鉱物
油系潤滑油、若しくは重金属を含まないスレッドコンパ
ウンドを使用する場合であっても、繰り返しの締め付
け、締め戻し操作に耐えることができ、優れた耐焼き付
き性を発揮することができる。
In the threaded joint of the present invention, by performing the above-described plating treatment, lubrication-free, that is, even when no grease is used, or mineral oil-based lubricating oil or heavy metal as a lubricant is used. Even when a thread compound that does not include the thread compound is used, it can withstand repeated tightening and tightening operations, and can exhibit excellent seizure resistance.

【0035】これにより、重金属による環境汚染の問題
はなくなるとともに、当然に、表面処理として、二硫化
モリブデンを使用することもないので、硫化水素腐食の
問題もない。さらに、従来、継手表面にリン酸や蓚酸等
の化成処理を実施していたのであるが、これらの環境に
悪影響を及ぼす処理作業も不要となり、環境保全性をさ
らに向上させることができる。
This eliminates the problem of environmental pollution due to heavy metals, and of course does not use molybdenum disulfide as a surface treatment, so there is no problem of hydrogen sulfide corrosion. Furthermore, conventionally, chemical conversion treatments such as phosphoric acid and oxalic acid have been performed on the joint surface. However, such a treatment operation that adversely affects the environment is not required, and the environmental preservation can be further improved.

【0036】本発明のネジ継手では、上述した耐気密性
に優れた継手の構成と、耐焼き付き性に優れた継手の構
成とを組み合わせることができる。この場合には、それ
ぞれの構成が有する特徴が発揮され、耐気密性と耐焼き
付き性とを兼備し、優れた環境保全性を発揮する油井用
ネジ継手を提供することができる。
In the threaded joint according to the present invention, the above-described structure of the joint having excellent airtightness and the structure of the joint having excellent seizure resistance can be combined. In this case, it is possible to provide a threaded joint for oil wells that exhibits the features of the respective configurations, has both airtightness resistance and seizure resistance, and exhibits excellent environmental conservation.

【0037】[0037]

【実施例】本発明の油井管用ネジ継手が発揮する耐気密
性および耐焼き付き性の効果を確認するため、前記の図
3に示すカップリング方式の継手を用いて、実施例1、
2の試験を実施した。 (実施例1)継手の耐気密性を確認するため、鋼管寸法
が外径139.7mm×肉厚7.72mmで、引張強度が1035MPa(15
0ksi)の供試管を準備して内圧試験を行った。具体的な
継手寸法は、ピン部内半径R1が63.2mm、金属密封部外
半径R2が66.5mm、ボックス部外半径R3が77.2mmであ
り、縦弾性係数Eは21000kg/mm2である。
EXAMPLE In order to confirm the effects of airtightness and seizure resistance exhibited by the oil country tubular goods threaded joint of the present invention, using the coupling type joint shown in FIG.
Two tests were performed. (Example 1) In order to confirm the airtightness of the joint, the dimensions of the steel pipe were 139.7 mm in outer diameter × 7.72 mm in wall thickness, and the tensile strength was 1035 MPa (15 mm).
An internal pressure test was performed by preparing a test tube of 0 ksi). The specific joint dimensions are as follows: the inner radius R1 of the pin portion is 63.2 mm, the outer radius R2 of the metal sealing portion is 66.5 mm, the outer radius R3 of the box portion is 77.2 mm, and the longitudinal elastic modulus E is 21000 kg / mm 2 .

【0038】継手の締め付け状態での干渉量δは0.2mm
と0.5mmの2条件とし、内圧Piを0〜100MPaの範囲で変
動させて、金属密封部における接触面圧σr(MPa)との
関係から内面流体の漏洩有無を調査した。
The interference amount δ when the joint is tightened is 0.2 mm
The internal pressure Pi was varied in the range of 0 to 100 MPa, and the presence or absence of leakage of the internal fluid was investigated from the relationship with the contact surface pressure σr (MPa) in the metal sealing portion.

【0039】図4は、実施例1による内圧試験での内面
流体の漏洩状況を示す図である。同図に示すように、σ
r(MPa)≧Pi(MPa)の条件を満足する場合には、耐気
密性を確保することができるが、その他の条件では、内
面流体の漏洩が発生している。 (実施例2)継手の耐焼き付き性を確認するため、鋼管
寸法が外径177.8mm×肉厚10.36mmで、材質が13%Cr鋼と
高合金鋼(25%Cr−35%Ni)の供試管を使用して、AP
I(米国石油協会)にて規定する締め戻し試験を実施し
た。締め戻し回数は、APIがチュービング評価方法と
して規定する10回を採用した。さらに、締め付け速度は
2rpmとした。
FIG. 4 is a diagram showing the state of leakage of the internal fluid in the internal pressure test according to the first embodiment. As shown in FIG.
When the condition of r (MPa) ≧ Pi (MPa) is satisfied, airtightness can be ensured, but under other conditions, leakage of the inner surface fluid occurs. (Example 2) In order to confirm the seizure resistance of the joint, a steel pipe with dimensions of 177.8 mm in outer diameter x 10.36 mm in wall thickness and 13% Cr steel and high alloy steel (25% Cr-35% Ni) was used. Using test tubes, AP
A tightening test specified by I (American Petroleum Institute) was performed. As the number of times of reconciliation, 10 times specified by the API as a tubing evaluation method were adopted. Further, the tightening speed was 2 rpm.

【0040】継手の表面処理は、ボックス部にCuメッ
キ、ZnメッキおよびNiメッキの各処理を施し、ピン部は
ネジ加工ままとした。このとき、ピン部の金属密封部外
径は、締め付け状態での干渉量δが適正になるように、
メッキ膜厚Wtに応じて、加工代Δdを増加している。す
なわち、目安となる加工代は、Δd=2Wtとしている。
この加工代Δdやメッキ処理の膜厚およびビッカース硬
度Hvは表1に示す。
For the surface treatment of the joint, the box portion was subjected to each of Cu plating, Zn plating and Ni plating, and the pin portion was kept threaded. At this time, the outer diameter of the metal sealing portion of the pin portion, so that the interference amount δ in the tightened state is appropriate,
The processing allowance Δd is increased according to the plating film thickness Wt. That is, the machining allowance serving as a standard is Δd = 2Wt.
Table 1 shows the machining allowance Δd, the thickness of the plating process, and the Vickers hardness Hv.

【0041】継手の潤滑条件としては、潤滑剤を使用し
ない場合と、重金属を含まないスレッドコンパウンドを
潤滑剤として使用する場合の2条件とした。これらの条
件によって実施した締め戻し試験結果を表1に示す。
The lubrication conditions for the joint were two conditions, ie, when no lubricant was used and when a thread compound containing no heavy metal was used as the lubricant. Table 1 shows the results of the tightening test performed under these conditions.

【0042】[0042]

【表1】 表1から、締め戻し試験によって良好な耐焼き付き性を
得るためには、メッキ処理が本発明で規定する膜厚およ
びビッカース硬度の条件を満足する必要があることが分
かる(No.2、3、7、8、9)。高合金鋼の供試管で
は、潤滑剤を使用しない場合に耐焼き付き性の低下がみ
られたが(No.6)、重金属を含まないスレッドコンパ
ウンドの適用によって十分な耐焼き付き性が得られるこ
とが明らかになった(No.7)。
[Table 1] From Table 1, it can be seen that in order to obtain good seizure resistance by the retightening test, the plating treatment needs to satisfy the conditions of the film thickness and Vickers hardness specified in the present invention (No. 2, 3, 7, 8, 9). In high-alloy steel test tubes, seizure resistance was reduced when no lubricant was used (No. 6). However, application of thread compounds that do not contain heavy metals can provide sufficient seizure resistance. It became clear (No. 7).

【0043】さらに、メッキ処理で厚い膜厚を施す場合
には、金属密封部における締め付け状態での干渉量δが
適正になるように、加工代Δdを確保すべきであること
が分かる。
Further, when a thick film is formed by plating, it can be seen that the machining allowance Δd should be ensured so that the interference amount δ in the tightened state in the metal sealing portion becomes appropriate.

【0044】[0044]

【発明の効果】本発明の油井用ネジ継手によれば、締め
付け状態における金属密封部での接触面圧および干渉量
を、負荷内圧との関係で適正にすることによって、耐気
密性を向上させることができ、CO2やH2S等の有毒ガス
を環境中に漏らすことがないので、優れた環境保全性を
発揮することができる。
According to the threaded joint for oil wells of the present invention, the airtightness is improved by optimizing the contact surface pressure and the amount of interference at the metal sealing portion in the tightened state in relation to the load internal pressure. Since no toxic gas such as CO 2 or H 2 S is leaked into the environment, excellent environmental preservation can be exhibited.

【0045】また、表面処理としてピン部またはボック
ス部のいずれか一方に所定のメッキ処理を施すことによ
って、耐焼き付き性が確保でき、潤滑剤を使用しない場
合でも、若しくは環境汚染の恐れがない潤滑剤を使用す
る場合でも、焼き付きを発生することなく締め付け、締
め戻しが可能となり、環境保全に優れるとともに、作業
性の改善が可能となる。
By subjecting either the pin portion or the box portion to a predetermined plating treatment as a surface treatment, seizure resistance can be ensured, and lubrication without using a lubricant or environmental pollution can be ensured. Even when an agent is used, tightening and retightening can be performed without occurrence of seizure, thereby achieving excellent environmental protection and improving workability.

【0046】さらに、本発明の油井用ネジ継手では、こ
れらの構成を組み合わせることによって、優れた耐気密
性と耐焼き付き性とを兼備することができ、著しく環境
保全性を向上させることができる。
Further, in the oil well threaded joint of the present invention, by combining these structures, excellent airtightness resistance and seizure resistance can be obtained, and the environmental preservation can be remarkably improved.

【図面の簡単な説明】[Brief description of the drawings]

【図1】従来のバットレスタイプのネジ継手を示す模式
的一部破断縦断面図である。
FIG. 1 is a schematic partially broken longitudinal sectional view showing a conventional buttress type threaded joint.

【図2】従来のトルクショルダー形成用ネジ無し肩部を
有するネジ継手の要部を示す模式的縦断図である。
FIG. 2 is a schematic longitudinal sectional view showing a main part of a conventional threaded joint having a threadless shoulder for forming a torque shoulder.

【図3】本発明のトルクショルダー形成用ネジ無し肩部
を有するネジ継手の要部を示す模式的縦断図である。
FIG. 3 is a schematic longitudinal sectional view showing a main part of a threaded joint having a threadless shoulder for forming a torque shoulder according to the present invention.

【図4】実施例1による内圧試験での内面流体の漏洩状
況を示す図である。
FIG. 4 is a diagram showing a state of leakage of an internal fluid in an internal pressure test according to the first embodiment.

【符号の説明】[Explanation of symbols]

11:ピン部、 12:テーパ雄ネジ 13:ネジ無し肩部、 14:金属密封部 21:ボックス部、 22:テーパ雌ネジ 23:受け部 11: Pin part, 12: Tapered male screw 13: Shoulder without screw, 14: Metal seal part 21: Box part, 22: Tapered female screw 23: Receiving part

Claims (3)

【特許請求の範囲】[Claims] 【請求項1】先端にネジ無し肩部が形成されたテーパ雄
ネジを管端外周面に有するピン部と、前記のネジ無し肩
部が当接する受け部が形成されたテーパ雌ネジを内周面
に有するボックス部とが相互に接触して金属密封部を形
成する油井管用ネジ継手であって、前記金属密封部にお
ける内圧負荷状態での接触面圧σr(MPa)が下記(a)〜(c)
式を満たすことを特徴とする環境保全性に優れた油井管
用ネジ継手。 【数1】 ただし、Pi:内圧 (MPa) Pm:締め付け状態での金属密封部の接触面圧(MPa) δ :干渉量(mm) E :縦弾性係数 R1:ピン部の内半径(mm) R2:金属密封部の外半径(mm) R3:ボックス部の外半径(mm)
An inner circumference of a pin having a tapered male screw having a threadless shoulder at the tip on the outer peripheral surface of a pipe end and a tapered female screw having a receiving portion with which the screwless shoulder abuts. A threaded joint for an oil country tubular good in which a box part having a surface is in contact with each other to form a metal sealing part, wherein a contact surface pressure σr (MPa) in an internal pressure load state in the metal sealing part has the following (a) to (a). c)
A threaded joint for oil country tubular goods with excellent environmental preservation, which satisfies the formula. (Equation 1) However, Pi: internal pressure (MPa) Pm: contact surface pressure of metal sealing part in tightened state (MPa) δ: interference amount (mm) E: longitudinal elastic modulus R1: inner radius of pin part (mm) R2: metal sealing Outer radius of part (mm) R3: Outer radius of box part (mm)
【請求項2】先端にネジ無し肩部が形成されたテーパ雄
ネジを管端外周面に有するピン部と、前記のネジ無し肩
部が当接する受け部が形成されたテーパ雌ネジを内周面
に有するボックス部とが相互に接触して金属密封部を形
成する油井管用ネジ継手であって、前記ピン部またはボ
ックス部のいずれか一方の金属密封部に施されたメッキ
処理の膜厚を7〜50μとし、ビッカース硬度で300以下
とすることを特徴とする環境保全性に優れた油井管用ネ
ジ継手。
2. A pin having a tapered male screw having a threadless shoulder at its tip on the outer peripheral surface of a tube end, and a tapered female screw having a receiving portion with which said screwless shoulder abuts. An oil country tubular good threaded joint in which a box portion having a surface is in contact with each other to form a metal sealing portion, wherein a thickness of a plating process applied to one of the pin portion and the box portion is performed. A threaded joint for oil country tubular goods excellent in environmental preservation, characterized in that the thickness is 7 to 50μ and the Vickers hardness is 300 or less.
【請求項3】上記請求項1に記載の油井管用ネジ継手で
あって、さらにピン部またはボックス部のいずれか一方
の金属密封部に施されたメッキ処理の膜厚Wtを7〜50μ
とし、ビッカース硬度で300以下とすることを特徴とす
る環境保全性に優れた油井管用ネジ継手。このとき、金
属密封部の外半径R2(mm)は、メッキ処理前の外半径
R2'(mm)とした場合に、R2=R2'+0.001Wtの関係を
満足する
3. The threaded joint for an oil country tubular good according to claim 1, wherein a thickness Wt of a plating process applied to one of the metal sealing portion of the pin portion and the box portion is 7 to 50 μm.
A threaded joint for oil country tubular goods with excellent environmental preservation, characterized by a Vickers hardness of 300 or less. At this time, the outer radius R2 (mm) of the metal sealing portion satisfies the relationship of R2 = R2 '+ 0.001 Wt when the outer radius is R2' (mm) before plating.
JP2000323913A 2000-10-24 2000-10-24 Oil well pipe screw joint with excellency in environmental conservation Pending JP2002130552A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2000323913A JP2002130552A (en) 2000-10-24 2000-10-24 Oil well pipe screw joint with excellency in environmental conservation

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2000323913A JP2002130552A (en) 2000-10-24 2000-10-24 Oil well pipe screw joint with excellency in environmental conservation

Publications (1)

Publication Number Publication Date
JP2002130552A true JP2002130552A (en) 2002-05-09

Family

ID=18801522

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2000323913A Pending JP2002130552A (en) 2000-10-24 2000-10-24 Oil well pipe screw joint with excellency in environmental conservation

Country Status (1)

Country Link
JP (1) JP2002130552A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005351324A (en) * 2004-06-09 2005-12-22 Metal One Corp Screw joint for oil well pipe
JP2009150512A (en) * 2007-12-21 2009-07-09 Hiroshima Univ Method of preventing seizure at connecting point of pair of metal members and connection structure of pair of metal members
WO2013057926A1 (en) 2011-10-17 2013-04-25 Jfeスチール株式会社 Threaded coupling for pipe

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5817285A (en) * 1981-07-23 1983-02-01 住友金属工業株式会社 Joint for oil well pipe
JPH0610154A (en) * 1992-06-26 1994-01-18 Kawasaki Steel Corp Method for treating surface of oil well pipe joint
JPH06346988A (en) * 1993-06-04 1994-12-20 Nippon Steel Corp Oil well pipe joint and surface treatment method thereof
JPH11108264A (en) * 1997-09-30 1999-04-20 Nippon Steel Corp Oil well pipe joint

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5817285A (en) * 1981-07-23 1983-02-01 住友金属工業株式会社 Joint for oil well pipe
JPH0610154A (en) * 1992-06-26 1994-01-18 Kawasaki Steel Corp Method for treating surface of oil well pipe joint
JPH06346988A (en) * 1993-06-04 1994-12-20 Nippon Steel Corp Oil well pipe joint and surface treatment method thereof
JPH11108264A (en) * 1997-09-30 1999-04-20 Nippon Steel Corp Oil well pipe joint

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005351324A (en) * 2004-06-09 2005-12-22 Metal One Corp Screw joint for oil well pipe
WO2005121622A1 (en) * 2004-06-09 2005-12-22 Metal One Corporation Screw coupling for oil well pipe
JP2009150512A (en) * 2007-12-21 2009-07-09 Hiroshima Univ Method of preventing seizure at connecting point of pair of metal members and connection structure of pair of metal members
WO2013057926A1 (en) 2011-10-17 2013-04-25 Jfeスチール株式会社 Threaded coupling for pipe
JP2013087829A (en) * 2011-10-17 2013-05-13 Jfe Steel Corp Screw joint for pipe
CN103352662A (en) * 2011-10-17 2013-10-16 杰富意钢铁株式会社 Threaded coupling for pipe
AU2012324340B2 (en) * 2011-10-17 2016-01-07 Jfe Steel Corporation Threaded coupling for pipe
CN103352662B (en) * 2011-10-17 2016-08-10 杰富意钢铁株式会社 The screwed connection of pipe
CN103352662B9 (en) * 2011-10-17 2016-09-28 杰富意钢铁株式会社 The screwed connection of pipe
US9470345B2 (en) 2011-10-17 2016-10-18 Jfe Steel Corporation Threaded joint for pipes

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